It is known for electronic devices to display both a main image representing useful information relating to the device and a background image. An example is shown in FIG. 1A, which illustrates a mobile telephone 1000 comprising a keypad 1020 and a display 1010. The display shows a combination of two distinct images. The first, shown in FIG. 1B, is a main image and includes useful information such as the name of the mobile telephone service carrier (XX), the name of the user (Andy), menu selection information (Menu and Names), a reception bar on the right indicating the strength of a signal received by the mobile phone, and a power bar on the left indicating the power remaining in the battery. Thus, it will be clear that the main image need not be a single unitary image, but also can correspond to a plurality of separate icons or other images displayed at the same time.
This main image is superimposed on a background image, shown in FIG. 1C. In this example, the background image simply comprises a number of wavy lines. However, it could comprise any image, such as a picture, a photograph or an animated image. Again, the background image need not be a single unitary image, but also can correspond to a plurality of separate icons or other images displayed at the same time. The background and main images, or parts thereof, may also be video clips and the like.
In the example shown in FIG. 1, a digital clock could be included at the top right of the main image. Alternatively, the main image could include a representation of an analogue clock. Thus, the main image may also be animated. As an alternative, the clock could be included in the background image instead of the main image. Thus, the elements to be included in the main image and the background image are to some extent interchangeable.
In general, the main image will change during use of the phone. For example, if an incoming call is received, the main image will be altered to reflect this to the user. In particular, it is well-known for the main image to change to display the name and/or number of the caller. Similarly, if the user wishes to make a phone call, he may use an address book provided in the phone. As the user scrolls through the address book, the main image will change to guide him or her through the address book. Similarly, the main image will change as the user is guided through different levels of the menu system provided in the phone.
However, the background image need not, and generally does not, change as the main image changes. Such a background image is commonly referred to as a wallpaper image since it can comprise a repeated pattern and appear similar to conventional wallpaper used for interior decoration. Generally, the wallpaper or background image is decorative, although it may also have an information-providing function, such as the clock discussed above.
It is known to store several background images in the phone and for the user to be able to set manually which background image is displayed.
It is also known for mobile phones to “deactivate” after the phone has not been used for a certain period of time. In one example, the phone comprises a conventional liquid crystal display (LCD) device with a backlight. If the phone has not been used for a predetermined period of time, the phone enters a sleep mode in which the backlight is switched off to save energy. In this specification, the term “deactivate” and like terms include, for example, switching off of the backlight. Of course, the LCD may also be front lit.
A mobile phone or other electronic device may have any one or more of several different kinds of deactivation. In the example discussed above, another instance of deactivation may be to lock the keypad, for example after a further predetermined period has elapsed following switching off of the backlight. If the keypad is locked, then pressing of the keys will not control the phone in the way required by the user until a predetermined key or combination of keys has been pressed to unlock the keypad. Pressing the correct key or combination of keys will not only unlock the keypad, it will also switch the backlight on again.
In this example, another instance of deactivation may be to enter a sleep mode and switch off the display altogether or to display an energy-saving display, such as an unlit, mostly black display, with a clock. The phone may enter the sleep mode, for example, after a further predetermined period has elapsed following locking of the keypad. Another instance of deactivation may be to switch off the phone completely. The phone could also be deactivated after the user finishes making a call or when the user enters an instruction for deactivation.